R.S Aggarwal Math book for all exam in Hindi offline i. This is latest book for Math in Hindi.
This is very useful for Railway and all one Day exams. Math all topic is cover in book.
Topic in Railway Group D and NTPC Math Solved Paper in Hindi

संख्या पद्धति (Number System)
दशमलव भिन्न (Decimal Number)
घातांक तथा करणी (Indices and Surds)
सरलीकरण (Simplification)
लघुत्तम समापवर्त्य एवं महत्तम समापवर्तक
प्रतिशत (Percentage)
लाभ और हानि (Profit and loss)
छूट (Discount)
अनुपात एवं समानुपात (Ratio & Proportion)
साझेदारी (Partnership)
कार्य एवं समय (Work & Time)
मिश्रण (Alligation)
पाइप एवं टंकी (Pipe & Cistern)
साधारण ब्याज (Simpe Interest)
चक्रवृद्धि ब्याज (Compound Interest)
आयु संबंधी प्रश्न (Problem Based on age)
औसत (Average)
चाल समय और दूरी (Speed,Time and Distance)
रेलगाड़ी (Train)
नाव एवं धारा (Boat & Stream)